In various signal transmission schemes, signals are amplified (e.g., by a power amplifier) before transmission. As such, power amplifiers are generally included in a typical communication system. As an example, in a base station of a wireless communication system, a power amplifier may be used to amplify signals before they are transmitted to different clients.
Generally, power amplifiers may be designed to operate optimally within a certain peak-to-average ratio (PAR). However, signals in many communication systems, such as the wideband code division multiple access (WCDMA) and the orthogonal frequency-division multiplexing (OFDM) systems, may often have a PAR that may adversely affect the performance of power amplifiers. Accordingly, in order to increase the efficiency of a power amplifier, the dynamic range of input signals (e.g., the ratio between the largest and smallest magnitudes of the input signals) may need to be reduced before being transmitted to the power amplifier.
Crest factor reduction (CFR) is a technique that may be used to limit the dynamic range of signals in such systems. As an example, in a remote radio head (RRH) system (a typical subsystem in a communication base system), a CFR module may be used to scale input signals before they are transmitted to the power amplifier module. One of the more common techniques that may be employed by a CFR module is peak cancellation.
In a peak cancellation crest factor reduction system, scaled cancellation pulses are subtracted from the original input signals. In order to generate the cancellation pulses, scaling factors need to be calculated for peaks in the input signals. However, existing techniques for obtaining scaling factors may be resource intensive. As such, it may be challenging to implement an efficient CFR module on an integrated circuit device with limited hardware resources. For example, conventional implementations of CFR modules may include resource-intensive circuitry such as divider circuits.